As of Wednesday, Ducey had about 36% of the vote with an estimated 97% of precincts reporting. Scott Smith, former mayor of Mesa, came in second with 22% of the vote. Four other candidates rounded out the field.

Ducey will face off against Democrat Fred DuVal to succeed Gov. Jan Brewer in the heavily Republican state. DuVal, a White House staffer during the Bill Clinton administration and former chairman with the Arizona Board of Regents, ran unopposed in the primary.

The Tuesday election came a day after the U.S. 10th Circuit Court of Appeals in Denver heard arguments on the constitutionality of laws in Arizona and Kansas requiring residents to prove citizenship through a passport or birth certificate before they can register to vote in state and local elections. The states' rules are stricter than federal law, which requires a voter simply to affirm U.S. citizenship in writing.

As a result, Arizona held a two-tiered primary election. Voters who had not proved their U.S. citizenship to the state’s satisfaction were given separate ballots allowing them to vote for U.S. Congress — not for governor or any other state offices. Those who had proved their citizenship were given a regular ballot with all the races.

Supporters argue that such laws prevent voter fraud. Opponents maintain that the real motivation is to make it more difficult for minorities and the poor to vote.

One day before Arizona’s primary election, the U.S. 10th Circuit Court of Appeals in Denver heard arguments Monday on the constitutionality of voters having to prove citizenship through a passport or birth certificate before they can register to vote.

Nurse Nina Pham — once the upbeat face of the Dallas hospital that confronted the country’s first Ebola case — sued the hospital’s parent company Monday, alleging that it had failed to protect her before and after she was diagnosed with the deadly disease last fall.

With no political solution in sight, Congress faces another deadline to fund the Homeland Security Department by midnight Friday – a do-over of last week's bitter battle as Republicans try to stop President Obama's immigration plans.

Hours after Tamir Rice’s family angrily criticized Cleveland for contending in legal documents that the 12-year-old was to blame for his death at the hands of a police officer, the mayor apologized Monday and said the city would amend its court filing.